I'm used to iptables and I can't find a way to do this with firewalld.
I need to redirect the output traffic of one port back inside in the same port, basically this:
iptables -t nat -A OUTPUT -p tcp ...

Suppose I wanted to use ipfw to throttle uploads to youtube. The uploads are made to upload.youtube.com but this domain resolves into multiple different IPs (which also appear to change over time).
...

I have followed the below steps to disable the firewall in Linux. After reboot, again firewall is enabled. How to disable firewall permanently?
Login as the root user.
Next enter the following three ...

Im setting up a realtime gameserver fps-game, and then i need to configure ports.
Just to mention, i will setup multiple servers for this game on the same ip address,
which means i must open multiple ...

My proxy is Squid as an external machine. My router is a WRT54GL with tomato.
On the router, I wrote this for the firewall script. It nicely connects to the proxy, but when try to visit any page it ...

Using OpenWrt Backfire 10.03.1 on Linksys WRT54GL.
Till today my ISP's modem used to loopback all traffic with self-destination IP back to itself.
(for example if my WAN IP is 8.8.8.8 and I perform ...

I've recently set up a Debian Wheezy server with OpenVPN to help out some friends in areas where internet censorship is a problem (including the blocking of VPN traffic in general). To overcome this, ...

I have manually edited the /etc/sysconfig/iptables file in my CentOs 7.x installation , I have two entries and two processes running at the respective ports.
I am able to telnet/access port 2181 but ...

We are using the squid proxy in our setup and implemented as transparent proxy with user authentication.
Before couple of days, while we are trying to setup the iptables the squid started performing ...

I have run these commands (tried switching the order too) because I want to set up a firewall on my laptop so that nobody can connect to it (except of course in response to a connection I've made):
...

My ISP provides me with native IPv6 (unfortunately DS-Lite for v4) and I'm using SLAAC for the clients in my local network behind a broadband router.
As I don't trust the router (which is configured ...

(Note: I moved this question from StackOverflow, because it's to be considered off-topic there, better fits here, and still unsolved)
I have a udp client using luasocket, basically doing this (with a ...

What I mean by ``directly communicate''
Does it ever need to receive packets with the gateway's IP address as the source IP address, or send packets with the gateway's IP address as the destination ...

I created 2 VMs (CentOS6.5) on Windows Azure for Postgresql database and HA cluster, everything works fine except when I set iptables service on, the endpoint load-balanced set is down.
for security ...

I need to allow some users who only have access to the intranet to access one specific internet site. I'm doing this by using Nginx as a reverse proxy. To test this, I would like to block all internet ...

I need to do redirect port 443 on all interfaces to 8080 on one interface using iptables on a box with 2 NICs.
I also need to block pretty much anything else on those interfaces.
Here is my iptables ...

Good day,
I'm using a lot of WINE apps under Linux which work just fine, but one thing I am specifically looking for right now is to block their access to the internet (outgoing), with exception of ...

I have a few ubuntu servers in various geographies. I want to block all outgoing connections from all ubuntu machines (all processes) to several domains, e.g. www.server.com. I know iptables can block ...

I have multiple servers in my LAN (which I'll refer to as Box1), and they are all able to make outgoing SSH connections, except one that stopped recently, which I'll refer to as Box2 (actually, I'm ...

There are a lot of tutorials how to share network connection with your usb wifi adapter and I tried lots of them but it is still not working. Can you please help me with my problem. Here is my network ...

I'm aware of other questions with the same topic, but I couldn't get it to work.
I'd like to forward inside my local network all traffic from ip1 to ip2. Only from inside the network, no outside.
I ...

Blocking all ports(in and out) is easy but it's hard with the word "except". I don't know any rules that satisfies the condition.
PS: I know this question is nothing new. But in fact, I didn't find ...